Nonwoven fabric and fastening system that include an auto-adhesive material

ABSTRACT

In some embodiments, a nonwoven fabric includes a first web that is at least partially formed of extruded strands which include an auto-adhesive material. The nonwoven fabric is adapted to be bonded to another item that includes a similar auto-adhesive material. In other embodiments, a method of forming a nonwoven fabric includes extruding a plurality of strands that are formed of an auto-adhesive material. The method further includes routing the plurality of strands toward a moving support, depositing the plurality of strands onto the moving support, and then stabilizing the plurality of strands to form a web. In other embodiments, a fastening system includes a nonwoven fabric that has a web which is formed of a plurality of extruded strands that include an auto-adhesive material. The fastening system further includes a foam layer that has a surface with a plurality of free-standing struts that include a similar auto-adhesive material.

FIELD OF THE INVENTION

This invention relates to a nonwoven fabric, fastening system andmethod, and in particular to a nonwoven fabric, fastening system andmethod that include an auto-adhesive material.

BACKGROUND OF THE INVENTION

Many products include fastening systems that are used to join differentitems together, or different portions of the same item together. As anexample, a fastening system is typically used to adhere differentportions of a diaper together when a diaper is placed onto a child.

Some fastening systems are formed as an adhesive tape that includes asubstrate which has a tacky material covering some (or all) of thesubstrate. The tacky material covers one or both sides of the substratedepending on the type of fastening system.

One drawback with using adhesive tapes to join items together is thatthe tapes readily stick to unwanted areas which make them cumbersome tohandle. As an example, in some fastening systems that are used indiapers, the tacky material can undesirably stick to a child's tenderskin.

Another drawback with using adhesive tapes is that the tacky materialwhich is used in many adhesive tapes is easily contaminated (e.g., withdirt, baby powder, lotion, baby oil, etc.). The ability of an adhesivetape to effectively secure (and re-secure) items together is reduced asthe tacky material becomes contaminated.

Some adhesive tapes try to minimize unwanted sticking and/orcontamination of the tacky material by placing a temporary cover overthe tacky material. One disadvantage of incorporating a cover for thetacky material is that the consumer needs to perform some labor in orderto get the adhesive tape ready for fastening. In addition, the consumerneeds to dispose of a cover once it is removed from the rest of theadhesive tape.

Another type of fastening system incorporates hook and loop typeelements. These types of systems typically require the hook elements tobe on one item (or section) so that they can be secured to the loopelements on another item (or section).

One drawback with using hook and loop type elements is that the hook andloop type elements can be abrasive if they engage items other than eachother. As an example, when hook and loop type elements are used indiapers, the hook and loop type elements can undesirably abrade achild's tender skin. In addition, hook and loop type elements are oftenrelatively stiff such that they are difficult to incorporate into manytypes of products.

Some types of fastening systems include an auto-adhesive tape or film.An auto-adhesive tape or film typically has self-adhesive propertiessuch that auto-adhesive tapes or films are substantially non-adhesivewith respect to many other materials. Some auto-adhesive tapes or filmsmay be repeatedly adhered together and separated at service (e.g., room)temperature.

One of the advantages of auto-adhesive tapes or films is that they areuseful in a variety of applications. As an example, auto-adhesive tapesmay be especially well suited for many diaper-related applicationsbecause auto-adhesive tapes are not readily contaminated by materialsthat are commonly present in diaper changing environments (e.g., babylotions, oils and powders). In addition, auto-adhesive tapes do notreadily stick to unwanted areas or sections such that they are typicallyeasier to handle.

There are some drawbacks associated with auto-adhesive tapes or films.One of the drawbacks is that they must be formed into tapes or films.The manufacturing process that is associated with fabricating anauto-adhesive tape or film can be relatively burdensome. In addition,there are times where it may be difficult to incorporate an elongatedauto-adhesive tape or film into a consumer product.

Another drawback with auto-adhesive tapes or films is that they arerelatively smooth such that it may be difficult to supplement theauto-adhesive capability of the tape or film with any type of mechanicalattachment to the auto-adhesive tape or film. Auto-adhesive tapes orfilms typically do not include any auto-adhesive fibers or filamentssuch that it is difficult to adequately combine the auto-adhesive tapesor films with any type of hook and loop fastening system.

SUMMARY OF THE INVENTION

The present invention relates to a nonwoven fabric that includes a firstweb of extruded strands where at least some of the extruded strandsinclude an auto-adhesive material. The nonwoven fabric is adapted to bebonded to another item that includes a similar auto-adhesive material.

The nonwoven fabric may be used to join one item to another item, or tojoin one portion of an item to another portion of the same item. As anexample, different sections of the nonwoven fabric may be used to secureone portion of a diaper to another portion of a diaper.

As used herein, the term “auto-adhesive” refers to self-adhesiveproperties of a polymeric material. An auto-adhesive is substantiallynon-adhesive with respect to many other materials. Some auto-adhesivesmay be repeatedly adhered together and separated at service (e.g., room)temperature.

As used herein, the Peak Load of Auto-adhesive Strength represents aforce that is required to separate a nonwoven fabric that is attached toitself. In some embodiments, the nonwoven fabric may exhibit a Peak Loadof Auto-adhesive Strength value that is greater than about 100 grams perinch width of the nonwoven fabric.

In another form, the present invention relates to a method of forming anonwoven fabric. The method includes extruding a plurality of strandswhere at least some of the strands are formed of an auto-adhesivematerial. The method further includes routing the plurality of strandstoward a moving support and then depositing the plurality of strandsonto the moving support. The method further includes stabilizing theplurality of strands to form a web.

In some embodiments of the method, routing the plurality of strandstoward a moving support may include routing the plurality of strandsthrough a spin pack. In addition, extruding a plurality of strands mayinclude co-extruding a first component and a second component such thatthe auto-adhesive material is the first component and at least one othermaterial is the second component.

In another form, the present invention relates to a fastening system.The fastening system includes a nonwoven fabric that has a web which isformed of a plurality of extruded strands where at least some of thestrands include an auto-adhesive material. The fastening system furtherincludes a foam layer that has a surface with a plurality offree-standing struts. At least some of the free-standing struts includean auto-adhesive material that is similar to the auto-adhesive materialof the nonwoven fabric such that the free-stranding struts are adaptedto engage at least a portion of the plurality of strands on the web.

In some embodiments of the fastening system, at least some of theplurality of strands that include an auto-adhesive material may formauto-adhesive loops that engage the auto-adhesive free-standing struts.In addition, at least a portion of some of the auto-adhesivefree-standing struts may form auto-adhesive hooks such that theauto-adhesive hooks on the foam layer are adapted to engage theauto-adhesive loops on the web.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an example nonwoven fabric.

FIGS. 2A-2C are cross-section views illustrating example bicomponentstrands that may be used in the nonwoven fabric shown in FIG. 1.

FIG. 3 is a perspective view illustrating another example nonwovenfabric.

FIG. 4 is a side view of an example processing line that may be used toform a nonwoven fabric.

FIG. 5 is an enlarged view illustrating a portion of an example web thatmay be formed using the example processing line shown in FIG. 4.

FIG. 6 is a perspective view illustrating an example fastening system.

FIG. 7 is an enlarged side view of the example fastening system shown inFIG. 6.

FIG. 8 illustrates an example absorbent article that includes thefastening system shown in FIG. 6.

DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a nonwoven fabric 10 that includes a first web 12.The first web 12 is formed of extruded strands 14 that include anauto-adhesive material.

As used herein, nonwoven fabric refers to a web of material that hasbeen formed without use of weaving processes that typically produce astructure of individual strands which are interwoven in a repeatingmanner. The nonwoven fabric may be formed by a variety of processes(e.g. meltblowing, spunbonding, film aperturing and staple fibercarding).

Although only a portion of the first web 12 is shown in FIG. 1, itshould be noted that the first web 12 may be any size or shape. Inaddition, the first web 12 may be a variety of different thicknessdepending on the application where the nonwoven fabric 10 is used. Theextruded strands 14 may be formed through any extrusion process that isknown now or discovered in the future (e.g., meltblowing).

As used herein, the term “auto-adhesive” refers to self-adhesiveproperties of a material. An auto-adhesive is substantially non-adhesivewith respect to many other materials. Some auto-adhesives may berepeatedly adhered together and separated at service (e.g., room)temperature.

In some embodiments, the auto-adhesive material may be a polymericmaterial that includes thermoplastic elastomers. As an example, thethermoplastic elastomers may have molecules that include sequentialarrangements of unique combinations of monomer units. The thermoplasticelastomers should have relatively stable auto-adhesive properties and besubstantially non-adhesive with respect to other materials.

In addition, the auto-adhesive material may include a thermoplasticelastomer that has physical cross-links which restrict the elastomermobility (i.e., flow). Restricting the elastomeric mobility may promotethe auto-adhesive properties of a thermoplastic elastomer.

Some example thermoplastic elastomers that may be used in theauto-adhesive material include multiblock copolymers of radial, triblockand diblock structures including non-rubbery segments of mono- andpolycyclic aromatic hydrocarbons, and more particularly, mono- andpolycyclic arenes. As examples, mono- and polycyclic arenes may includesubstituted and unsubstituted poly(vinyl)arenes of monocyclic andbicyclic structure.

In some embodiments, the thermoplastic elastomers may includenon-rubbery segments of substituted or unsubstituted monocyclic arenesof sufficient segment molecular weight to assure phase separation atroom temperature. As examples, monocyclic arenes may include polystyreneand substituted polystyrenes that have monomer units such as styrene andalkyl substituted styrene (e.g., alpha methylstyrene and4-methylstyrene). Other examples include substituted or unsubstitutedpolycyclic arenes that have monomer units (e.g., 2-vinyl naphthalene and6-ethyl-2-vinyl naphthalene).

It should be noted that the thermoplastic elastomers may also includerubbery segments that are polymer blocks which may be composed ofhomopolymers of a monomer, or a copolymer that includes two or moremonomers selected from aliphatic conjugated diene compounds (e.g.,1,3-butadiene and isoprene). Some example rubbery materials includepolyisoprene, polybutadiene and styrene butadiene rubbers. Other examplerubbery materials include saturated olefin rubber of eitherethylene/butylene or ethylene/propylene copolymers, which may be derivedfrom the corresponding unsaturated polyalkylene moieties (e.g.,hydrogenated polybutadiene and polyisoprene).

In addition, the thermoplastic elastomer may be part of a styrenic blockcopolymer system that includes rubbery segments which may be saturatedby hydrogenating unsaturated precursors (e.g., astyrene-butadiene-styrene (SBS) block copolymer that has center ormid-segments which include a mixture of 1,4 and 1,2 isomers). As anexample, a -butadiene-styrene (SBS) block copolymer that includes centeror mid-segments which have a mixture of 1,4 and 1,2 isomers may behydrogenated to obtain (i) a styrene-ethylene-butylene-styrene (SEBS)block copolymer; or (ii) a styrene-ethylene-propylene-styrene (SEPS)block copolymer.

In some embodiments, the auto-adhesive material may include a mixture ofa polyethylene and a block copolymer. As an example, the auto-adhesivematerial may include a mixture of one or more block copolymers selectedfrom the group consisting ofpoly(styrene)-co-poly(ethylene-butylene)-co-poly(styrene) copolymer,poly(styrene)-co-poly(ethylene-butylene) copolymer, and a polyethylenepolymer. In some embodiments, the one or more block copolymers may bebetween about 30 weight percent to about 95 weight percent of theauto-adhesive material, and the polyethylene polymer may be betweenabout 5 weight percent to about 70 weight percent of the auto-adhesivematerial (wherein all weight percents are based on the total weightamount of the block copolymer and the polyethylene polymer that arepresent in the auto-adhesive layer).

As used herein, the Peak Load of Auto-adhesive Strength represents aforce that is required to separate the nonwoven fabric 10 when it isattached to itself. When the nonwoven fabric 10 is used as an adhesivecomponent, the Peak load of Auto-adhesive Strength should meet theadhesive strength requirement for a particular application. If anonwoven fabric 10 is used in a fastening system, the Peak Load ofAuto-adhesive Strength for the nonwoven fabric 10 needs to be highenough to prevent the fastening system from opening during use. Anonwoven fabric 10 that exhibits too low of a Peak Load of Auto-adhesiveStrength may not be suitable for some fastening system applications.

The nonwoven fabric 10 readily bonds to other items that include asimilar auto-adhesive material with a strength that is greater than thestrength which is generated when the nonwoven fabric 10 is bonded to anyother type of material (e.g., a bonding strength that is at least twiceas great). As an example, the nonwoven fabric 10 may exhibit a Peak Loadof Auto-Adhesive Strength value that is greater than about 100 grams perinch width of the nonwoven fabric 10 (about 118 grams per centimeterwidth of the layer), and up to about 2000 grams per inch width of thenonwoven fabric 10 (about 787 grams per centimeter width of the layer).The method by which the Peak Load of Auto-Adhesive Strength value for aweb is determined is set forth in U.S. Pat. No. 6,261,278 which isincorporated by reference herein.

The type of auto-adhesive material that is used to form the plurality ofstrands 14 will be selected based on (i) processing parameters; (ii)physical properties; (iii) packaging issues; and (iv) costs (among otherfactors). The first web 12 should have properties that are required fora particular product and/or process. The physical properties of theauto-adhesive material may be controlled to define properties for thenonwoven fabric 10 such as melting temperature, shear strength,crystallinity, elasticity, hardness, tensile strength, tackiness andheat stability (among other properties).

In some embodiments, the nonwoven fabric 10 may be made by melt spinningthermoplastic materials. This type of nonwoven fabric 10 may be referredto as a spunbond material.

Example methods for making spunbond polymeric materials are described inU.S. Pat. No. 4,692,618 to Dorschner et al., and U.S. Pat. No. 4,340,563to Appel et al. both of which disclose methods for making spunbondnonwoven webs from thermoplastic materials by extruding thethermoplastic material through a spinneret and drawing the extrudedmaterial into filaments with a stream of high velocity air to form arandom web on a collecting surface. U.S. Pat. No. 3,692,618 to Dorschneret al. discloses a process wherein bundles of polymeric filaments aredrawn with a plurality of eductive guns by very high speed air whileU.S. Pat. No. 4,340,563 to Appel et al. discloses a process whereinthermoplastic filaments are drawn through a single wide nozzle by astream of high velocity air. Some other example melt spinning processesare described in U.S. Pat. No. 3,338,992 to Kinney; U.S. Pat. No.3,341,394 to Kinney; U.S. Pat. No. 3,502,538 to Levy; U.S. Pat. No.3,502,763 to Hartmann; U.S. Pat. No. 3,909,009 to Hartmann; U.S. Pat.No. 3,542,615 to Dobo et al., and Canadian Patent Number 803,714 toHarmon.

In some embodiments, desirable physical properties may be incorporatedinto the nonwoven fabric 10 by forming the strands 14 out of amulticomponent or bicomponent material where at least of one thematerials in the bicomponent material is an auto-adhesive material. Theauto-adhesive material may be similar to any of the auto-adhesivematerials described above.

As used herein, strand refers to an elongated extrudate formed bypassing a polymer through a forming orifice (e.g., a die). A strand mayinclude a fiber, which is a discontinuous strand having a definitelength, or a filament, which is a continuous strand of material.

Some example methods for making a nonwoven fabric from multicomponent orbicomponent materials are disclosed. U.S. Pat. No. 4,068,036 toStanistreet, U.S. Pat. No. 3,423,266 to Davies et al., and U.S. Pat. No.3,595,731 to Davies et al. disclose methods for melt spinningbicomponent filaments to form a nonwoven fabric. The nonwoven fabric 10may be formed by cutting the meltspun strands into staple fibers, andthen forming a bonded carded web, or by laying the continuousbicomponent filaments onto a forming surface and thereafter bonding theweb.

FIGS. 2A-2C illustrate some example forms of bicomponent strands 14 thatmay be used to form web 12. The strands 14 include a first component 15and a second component 16 that are arranged in substantially distinctzones across the cross-section of the bicomponent strands 14 and extendalong the length of the bicomponent strands 14. The first component 15of the bicomponent strand includes an auto-adhesive material andconstitutes at least a portion of the peripheral surface 17 on thebicomponent strands 14. Since the first component 15 exhibits differentproperties than the second component 16, the strands 14 may exhibitproperties of the first and second components 15, 16.

The first and second components 15, 16 may be arranged in a side-by-sidearrangement as shown in FIG. 2A. FIG. 2B shows an eccentric sheath/corearrangement where the second component 16 is the core of the strand 14and first component 15 is the sheath of the strand 14. It should benoted that the resulting filaments or fibers may exhibit a high level ofnatural helical crimp in the sheath/core arrangement illustrated in FIG.2B. In addition, the first and second components 15, 16 may be formedinto a concentric sheath/core arrangement as shown in FIG. 2C.

Although the strands 14 are disclosed as bicomponent filaments orfibers, it should be understood that the nonwoven fabric 10 may includestrands 14 which have one, two or more components. In addition, thenonwoven fabric 10 may be formed of single component strands that arecombined with multicomponent strands. The type of materials that areselected for the first and second components 15, 16 will be based onprocessing parameters and the physical properties of the material (amongother factors).

It should be noted the auto-adhesive material may include additives. Inaddition, when the strands 14 are formed of a bicomponent (ormulticomponent) strands 14, some (or all) of components that form thestrands 14 may include additives. As an example, the strands 14 mayinclude pigments, anti-oxidants, stabilizers, surfactants, waxes, flowpromoters, plasticizers, nucleating agents and particulates (among otheradditives). In some embodiments, the additives may be included topromote processing of the strands 14 and/or web 12.

As shown in FIG. 3, the nonwoven fabric 10 may be formed of multiplewebs 12, 22, 32. The first web 12 of extruded strands 14 may be similarto first web 12 described above. The first web 12 may be bonded to asecond web 22 of extruded strands 14 such that the first and second webs12, 22 are positioned in laminar surface-to-surface relationship. Inaddition, the second web 22 may be bonded to a third web 32 such thatthe second and third webs 22, 32 are positioned in laminarsurface-to-surface relationship.

In some embodiments, the second and/or third webs 22, 32 may be aspunbond material while in other embodiments the second and/or thirdwebs 22, 32 may be made by meltblowing techniques. Some examplemeltblowing techniques are described in U.S. Pat. No. 4,041,203, thedisclosure of which is incorporated herein by reference. U.S. Pat. No.4,041,203 references the following publications on meltblowingtechniques which are also incorporated herein by reference: An articleentitled “Superfine Thermoplastic Fibers” appearing in INDUSTRIAL &ENGINEERING CHEMISTRY, Vol. 48, No. 8, pp. 1342-1346 which describeswork done at the Naval Research Laboratories in Washington, D.C.; NavalResearch Laboratory Report 111437, dated Apr. 15, 1954; U.S. Pat. Nos.3,715,251; 3,704,198; 3,676,242; and 3,595,245; and BritishSpecification No. 1,217,892.

Each of the second and third webs 22, 32 may have substantially the samecomposition as the first web 12 or have a different composition than thefirst web 12. In addition, the second and third webs 22, 32 may beformed from single component, bicomponent or multicomponent strands 14.

In some embodiments, the first, second and/or third webs 12, 22, 32 mayformed separately and then bonded together (e.g., by thermal pointbonding). It should be noted that when the first, second and possiblythird web are bonded together, and a common elastomeric polymer ispresent in the strands 14 that form the first, second and third webs 12,22, 32, the bonding between the first, second and third webs 12, 22, 32may be more durable.

In other embodiments, the first, second and third webs 12, 22, 32 may beformed in a continuous process wherein each of the first, second andthird webs 12, 22, 32 is formed one on top of the other. Both processesare described in U.S. Pat. No. 4,041,203, which has already beenincorporated herein by reference.

The types of materials that are selected for the extruded strands 14that make up the first, second and third webs 12, 22, 32 will be basedon processing parameters and the desired physical properties of thenonwoven fabric 10 (among other factors). The first, second and thirdwebs 12, 22, 32 may be attached together through any method that isknown now or discovered in the future. Although the first, second andthird webs 12, 22, 32 are partially shown as webs of the same size, itshould be noted that the first, second and third webs 12, 22, 32 may bedifferent sizes and/or shapes. In addition, the first, second and thirdwebs 12, 22, 32 may be the same (or different) thicknesses.

A method of forming a nonwoven fabric 10 will now be described withreference to FIG. 4. The method includes extruding a plurality ofstrands 14 where at least some of the strands 14 are formed of anauto-adhesive material. The method further includes routing theplurality of strands 14 toward a moving support 66 and depositing theplurality of strands 14 onto the moving support 66. The method furtherincludes stabilizing the plurality of strands 14 to form a web 12.

FIG. 4 shows an example processing line 40 that is arranged to produce aweb 12 that includes a plurality of bicomponent continuous strands 14(e.g., filaments or fibers). It should be understood that the processingline 40 may be adapted to form a nonwoven fabric 10 that includes one,two or multiple components in each strand 14. In addition, theprocessing line 40 may be adapted to form a nonwoven fabric 10 thatinclude single component strands 14 in combination with multicomponentstrands 14.

In the example embodiment that is illustrated in FIG. 4, the first andsecond components 15, 16 may be separately co-extruded in two differentextruders 41, 42. It should be noted that the first and second extruders41, 42 may be any extruder that is known now or discovered in thefuture.

In some embodiments, the first and second components 15, 16 are in theform of solid resin pellets (or particles) that are heated above theirmelting temperature and advanced along a path (e.g., by a rotatingauger). The first component 15 is routed through one conduit 46 whilethe second component 16 is simultaneously routed through another conduit48.

Both flow streams are directed into a spin pack 50 that initially formsthe strands 14. As an example, the spin pack 50 may include a plate thathas a plurality of holes or openings through which the extruded materialflows. The number of openings per square inch in the spin pack 50 mayrange from about 5 to about 500 openings per square inch. The size ofeach opening in the spin pack may vary from about 0.1 millimeter (mm) toabout 2.0 mm in diameter. It should be noted that the openings in thespin pack 50 may have a circular cross-section, or have a bilobal,trilobal, square, triangular, rectangular or oval cross-sectiondepending on the properties that are desired for the nonwoven fabric 10.

In the example embodiment that is illustrated in FIG. 4, the first andsecond components 15, 16 may be directed into the spin pack 50 and thenrouted through the spin pack 50 in such a manner that the secondcomponent 16 forms a core while the first component 15 forms a sheathwhich surrounds the core. As discussed above with regard to FIGS. 2A-2C,the bicomponent strands 14 may have a side by side configuration or acore/sheath design (among other possible configurations).

One bicomponent strand 14 will be formed for each opening formed in theplate within the spin pack 50. Each of the plurality of strands 14simultaneously exits the spin pack 50 at a first speed. The initialdiameter of each bicomponent strand 14 will be dictated by the size ofthe openings that are in the plate of the spin pack 50.

In some embodiments, the plurality of strands 14 are routed downwardlythrough a quench chamber 58 to form a plurality of cooled strands 14. Itshould be noted that directing the strands 14 downward allows gravity toassist in moving the strands 14. In addition, the downward movement mayaid in keeping the stands 14 separated from one another.

The strands 14 are contacted by one or more streams of air as thestrands move into the quench chamber 58. The velocity of the incomingair may be maintained or adjusted so that the strands 14 are efficientlycooled.

The plurality of strands are then routed to a draw unit 60 that may belocated below the quenching chamber 50 so as to again take advantage ofgravity. As used herein, drawing involves subjecting the cooled strands14 to pressurized air that draws (i.e., pulls) the molten strands 14which are exiting the spin pack 50 downward.

The downward force that is generated by the pressurized air in the drawunit 60 causes the molten strands 14 to be lengthened and elongated. Theamount that the diameter of the strands 14 is reduced depends uponseveral factors including (i) the number of molten strands 14 that aredrawn; (ii) the distance over which the strands 14 are drawn; (iii) thepressure and temperature of the air that is used to draw the strands 14;and (iv) the spin line tension (among other factors).

The cooled strands 14 are pulled within the draw unit 60 at a speed thatis faster than the speed at which the continuous molten strands 14 exitthe spin pack 50. The change in speed causes the molten strands to belengthened and reduced in cross-sectional area. The cooled strands 14may be completely solid upon exiting the draw unit 60.

The solid strands 14 are deposited onto a moving support 66 afterexiting the draw unit 60. As an example, the moving support 66 may be acontinuous forming wire or belt that is driven by a drive roll 68 andrevolves about a guide roll 70.

The moving support 66 may be constructed as a fine, medium or coarsemesh that has no openings or a plurality of openings. As examples, themoving support 66 may have a configuration that is similar to a standardwindow screen, or the moving support 66 may be tightly woven to resemblea wire that is commonly used by the paper industry in the formation ofpaper. A vacuum chamber 72 may be positioned below the moving support 66to facilitate accumulation of the strands 14 onto the moving support 66.

In some embodiments, the strands 14 accumulate on the moving support 66in a random orientation such that the accumulation of strands 14 at thispoint does not include any melt points or bonds that would stabilize thestrands 14 into a web. The thickness and basis weight of the strands 14is established in part by (i) the speed of the moving support 66; (ii)the number and diameter of the strands 14 that are deposited onto themoving support 66; and (iii) the speed at which the strands 14 are beingdeposited onto the moving support 66.

Depending on the type of processing line 40, the moving support 66 mayrout the plurality of strands 14 under a hot air knife 76 that directsone or more streams of hot air onto the plurality of strands 14. The hotair needs to be of sufficient temperature to melt some of the strands 14at points where the strands 14 contact, intersect or overlap otherstrands 14.

As shown in FIG. 5, the strands 14 adhere to adjacent strands 14 at meltpoints 78 to form a stabilized web 12. The number of melt points 78 thatform the web 12 is determined by a number of factors including: (i) thespeed of the moving support 66; (ii) the temperature of the hot air;(iii) the types of material that are in the strands 14; and (iv) thedegree to which the strands 14 are entangled (among other factors).

In some embodiments, the web 12 may be routed through a nip that isformed by a bond roll (not shown) and an anvil roll (not shown) whichare heated to an elevated temperature. As an example, the bond roll maycontain one or more protuberances that extend outward from the outercircumference of the bond roll. The protuberances may be sized andshaped to create a plurality of bonds in the web 12 as the web 12 passesthrough the bond roll and the anvil roll. Once the web 12 has bondsformed therein, the web 12 becomes a bonded web 12.

The exact number and location of the bonds in the bonded web 12 isdetermined by the position and configuration of the protuberances thatare on the outer circumference of the bond roll. As an example, at leastone bond per square inch may be formed in the bonded web 12, althoughembodiments are contemplated where the percent bonded area varies. As anexample, the percent bonded area may be from about 10% to about 30% ofthe total area of the web 12.

FIGS. 6 and 7 depict a fastening system 90. The fastening system 90includes a nonwoven fabric 10 that has a web 12 which is formed of aplurality of extruded strands 14 where at least some of the strands 14include an auto-adhesive material. The fastening system 90 includes afoam layer 91 that has a surface 92 (see FIG. 7) which is formed of aplurality of free-stranding struts 93. The free-standing struts 93 areadapted to engage at least a portion of the plurality of strands 14where at least some of the free-standing struts 93 include anauto-adhesive material that is similar to the auto-adhesive material ofthe nonwoven fabric 10.

It should be noted that the nonwoven fabric 10 may be similar to any ofthe nonwoven fabrics 10 that are described above. In addition, the foamlayer 91 may be similar to any of the foam layers that are described inU.S. patent application Ser. No. 10/956,613 filed, Sep. 30, 2004 andEuropean Patent 0235949A1. As an example, the foam layer 91 may be anopen cell foam.

The auto-adhesive materials that are used in the respective nonwovenfabric 10 and foam layer 91 may be similar to any of the auto-adhesivematerials described above. The types of auto-adhesive materials that areselected for the nonwoven fabric 10 and foam layer 91 that make up thefastening system 90 will be based on processing parameters and thedesired physical properties of the fastening system 90 (among otherfactors).

In some embodiments, at least some of the plurality of strands 14 thatinclude an auto-adhesive material may form auto-adhesive loops thatengage the auto-adhesive free-standing struts 93 of the foam layer 91.In addition, at least a portion of some of the auto-adhesivefree-standing struts 93 may form auto-adhesive hooks such that theauto-adhesive hooks are adapted to engage the auto-adhesive loops on theweb 12.

It should be noted that the extent to which the strands 14 form loopsand the free-standing struts 93 form hooks will depend in part on howthe respective nonwoven fabric 10 and foam layer 91 are fabricated. Asan example, the free-standing struts 93 may have diameters of about 500microns or less.

In some embodiments, the foam layer 91 may be reinforced by attaching asupport 94 to the foam layer 91. The support 94 may be attached to thefoam layer 91 by any means (e.g., adhesive lamination of the support 94to the foam layer 91 or formation of the foam layer 91 on the support94). As an example, the support 94 may be dipped into a liquid that iscured to form the foam layer 91. U.S. Pat. No. 6,613,113, issued toMinick et al. on Sep. 2, 2003 describes such a process.

Adding the support 94 to the foam layer 91 may improve strength and/orflexibility of the foam layer 91. Improving the strength and flexibilityof the foam layer 91 may increase the number of applications where thefastening system 90 may be used.

In some embodiments, the free-standing struts 93 of the foam layer 91may be treated to have increased surface roughness which may facilitateattachment of the free-standing struts 93 to the nonwoven fabric 10. Asan example, the free-standing struts 93 may be roughened by attachingparticles to them (e.g., microspheres, mineral filler, etc.).

In other embodiments, the free-standing struts 93 may be etched orotherwise treated (e.g., by chemical attack, laser ablation, electronbeam treatment, etc.) to remove portions of the surface material inindividual free-standing struts 93. U.S. Pat. No. 3,922,455, issued toBrumlik et al. on Nov. 25, 1975 describes some examples of texturedelements that may correspond to modified free-standing struts 93.

FIG. 8 illustrates an example disposable absorbent article 95 (shown asa training pant) that may include any of fastening systems 90 describedherein. The illustrated example absorbent article 95 is similar to thetraining pant disclosed in U.S. Pat. No. 6,562,167, issued to Coenen etal. on May 13, 2003 (which is incorporated herein by reference).

The example absorbent article 95 is illustrated in a partially fastenedmode in FIG. 8. In the illustrated example embodiment, the foam layer 91of the fastening system 90 is joined to front side panels 96 on thetraining pant 95 and a portion of the nonwoven fabric 10 is attached torear panels 97 on the training pant 95. The fastening system 90 securesthe training pant 95 about the waist of a wearer by engaging thenonwoven fabric 10 with the foam layer 91.

The nonwoven fabric 10 of the present invention may be useful in avariety of other applications. As examples, the nonwoven fabric 10 mayincorporated into other products such as adult incontinent products, bedpads, other catamenial devices, sanitary napkins, tampons, wipes, bibs,wound dressings, surgical capes or drapes, soiled garment bags, garbagebags, storage bags and product packaging. The nonwoven fabric 10 may beespecially well suited to diaper-related applications because theauto-adhesive material in the nonwoven fabric 10 is not readilycontaminated with many of the materials that are commonly present indiaper changing environments (e.g., baby lotions, oils and powders).

The nonwoven fabric 10 may be secured to diapers (or other products)using thermal bonding and/or adhesives (among other techniques). As anexample, one section of the nonwoven fabric 10 may be secured to oneportion of a diaper such that the section is designed to engage anothersection of the nonwoven fabric 10 (e.g., a landing zone) on anotherportion of the diaper.

As part of fabricating any articles or products that include thenonwoven fabric 10, multiple sections may be cut from the first web 12as the first web 12 is fed out from a continuous roll. The multiplesections may then be stacked for packaging or alternatively delivered asthe continuous roll. In some forms, the multiple sections may beinter-folded, o-folded and/or compressed into various geometric shapes.In addition, the nonwoven fabric 10 may be embossed with logos, useinstructions or any other design or information.

The nonwoven fabric 10 may also be decorative in color and/or shapedepending on consumer appeal. There are also embodiments that arecontemplated where the nonwoven fabric 10 has an unobtrusive productform such that the nonwoven fabric 10 does not interfere with theaesthetics of the products where the nonwoven fabric 10 is located.

While the invention has been described in detail with respect tospecific embodiments, it will be appreciated that there are variationsof, and equivalents to these embodiments. Accordingly, the scope of thepresent invention should be determined by the appended claims and anyequivalents thereto.

1-23. (canceled)
 24. A fastening system comprising: a nonwoven fabricthat includes a web which is formed of a plurality of extruded strandswhere at least some of the strands include an auto-adhesive material;and a foam layer that includes a surface having a plurality offree-stranding struts which are adapted to engage at least a portion ofthe plurality of strands, at least some of the free-stranding strutsincluding an auto-adhesive material that is similar to the auto-adhesivematerial in the nonwoven fabric.
 25. The fastening system as set forthin claim 24, wherein the plurality of free-standing struts havediameters of about 500 microns or less.
 26. The fastening system as setforth in claim 24, wherein the foam layer is an open-cell foam material.27. The fastening system as set forth in claim 24, wherein at least someof the plurality of strands that include an auto-adhesive material formauto-adhesive loops that engage the auto-adhesive free-standing struts.28. The fastening system as set forth in claim 27, wherein at least someof the auto-adhesive free-standing struts form auto-adhesive hooks suchthat each auto-adhesive hook is adapted to engage one of theauto-adhesive loops on the web.
 29. The fastening system of claim 24wherein the extruded strands in the web are formed by meltblowing. 30.The fastening system of claim 24 wherein the auto-adhesive material inthe nonwoven fabric readily bonds to the auto-adhesive material in thefoam layer with a strength that is at least twice as great as thestrength which is generated when the auto-adhesive material is bonded toany other type of material.
 31. The fastening system of claim 24,wherein the auto-adhesive material includes a polyethylene polymer. 32.The fastening system of claim 31 wherein the auto-adhesive materialincludes a mixture of the polyethylene polymer and a blend ofcopolymers.
 33. A nonwoven fabric comprising a first web of extrudedstrands, the extruded strands being formed of a first component and asecond component with the first component being at least partiallyformed of an auto-adhesive material.
 34. The nonwoven fabric of claim 33wherein the second component is formed of a polymeric material.
 35. Thenonwoven fabric of claim 33 wherein the extruded strands have across-section, a length and a peripheral surface, the first and secondcomponents being arranged in substantially distinct zones across thecross-section of the extruded strands and extending along the length ofthe extruded strands, the first component constituting at least aportion of the peripheral surface of the extruded strands along thelength of the extruded strands.
 36. The nonwoven fabric of claim 33further comprising a second web of extruded strands.
 37. The nonwovenfabric of claim 36 wherein the extruded strands that form the second webare polymeric strands.
 38. The nonwoven fabric of claim 36 furthercomprising a third web of extruded strands such that the second web isbetween the first web and the third web, the extruded strands of thethird web being the same material as the extruded strands of the firstweb.
 39. The nonwoven fabric of claim 33 wherein the first web readilybonds to other items that include a similar auto-adhesive material witha strength that is at least twice as great as the strength which isgenerated when the first web is bonded to any other type of material.40. The nonwoven fabric of claim 33 wherein the first web exhibits aPeak Load of Auto-adhesive Strength value that is greater than about 100grams per inch width of the first web.
 41. The nonwoven fabric of claim33 wherein the extruded strands are formed by meltblowing.
 42. Thenonwoven fabric of claim 33 wherein the extruded strands of the firstweb are continuous filaments.
 43. The nonwoven fabric of claim 33wherein the extruded strands of the web are fibers.
 44. The nonwovenfabric of claim 33 wherein the auto-adhesive material includes apolyethylene polymer.
 45. The nonwoven fabric of claim 44 wherein theauto-adhesive material includes a mixture of the polyethylene polymerand a blend of copolymers.
 46. A method of forming a nonwoven fabric,the method comprising: co-extruding a first component and a secondcomponent to form a plurality of strands, an auto-adhesive materialbeing the first component and at least one other material being thesecond component; routing the plurality of strands toward a movingsupport; depositing the plurality of strands onto the moving support;and stabilizing the plurality of strands to form a web.
 47. The methodof claim 46 wherein co-extruding a first component and a secondcomponent includes co-extruding a first component and a second componentsuch that the first component is formed on at least a portion of aperiphery of each of the strands.
 48. The method of claim 46 whereinco-extruding a first component and a second component includesco-extruding a plurality of continuous filaments.
 49. The method ofclaim 46 wherein co-extruding a first component and a second componentincludes co-extruding a plurality of fibers.
 50. The method of claim 46wherein routing the plurality of strands toward a moving supportincludes routing the plurality of strands through a spin pack.
 51. Themethod of claim 50 wherein routing the plurality of strands toward amoving support includes routing plurality of strands through a quenchchamber to cool the plurality of strands.
 52. The method of claim 46wherein stabilizing the plurality of strands to form a web includesbonding the strands to one another.
 53. The method of claim 46 whereinco-extruding a first component and a second component includesco-extruding a plurality of strands such that each of the strands is atleast partially formed of an auto-adhesive material.